Sexual selection and the fitness effects of meiotic drive in the Malaysian stalk-eyed fly.

Across the genome, each allele has an equal probability of segregating during meiosis and being passed onto the next generation. However, selfish genetic elements can arise that spread by enhancing their transmission at a cost to the rest of the genome. How and why these spread remains a fundamental question. Sex-linked meiotic drive genes typically reside within chromosomal inversions to maintain high linkage (an area of low recombination), but as such, accumulate heavy deleterious load. Intragenomic conflict exists between the drive gene which reduces the fitness and imposes costs to various life history traits (e.g: fertility, viability), and the rest of the genome, which attempts to evolve putative adaptations against these costs. This PhD project builds upon a decade of theoretical and experimental work on the X-linked meiotic drive system in the Malaysian stalk-eyed fly, Teleopsis dalmanni. This insect is characterised by extreme sexual selection and exaggerated secondary-sexual ornaments (eyespan) owing to evolved female mate preference for males with the widest eyespan. This work is therefore unique as it brings together both sexual selection and meiotic drive, and will be the first evidence of how sex ratio (SR) drive influences reproductive behaviour in wild populations.